1. Field of the Invention
This invention relates to a power switching system for an acoustic apparatus for switching the drive power transmission such that driven gears meshing with a main drive gear are selectively brought into mesh with a first or a second gear with switching of the direction of rotation of the main drive gear.
2. Description of the Prior Art
In an acoustic apparatus, the drive power transmission route from the motor is selectively switched to either a first or a second gear by switching the direction of rotation of the motor. More specifically, a main drive gear rotated by the motor is disposed between the first and second gears, the driven gear which is always in mesh with the main drive gear is supported on a rocking member, and the driven gear is caused to rock together with the rocking member according to the direction of rotation of the main drive gear, thus selectively transmitting the drive power of the main drive gear to either one of the first and second gears.
With this arrangement of the drive power switching system, the drive power of the motor can be switched to either one of the first and second gears by merely switching the direction of rotation of the motor. It is thus possible to simplify the drive power switching system. In a CD player as an example of the acoustic apparatus, as for the rotation of a pick-up drive motor the drive power is selectively switched between a pick-up drive mechanism as a first mechanism and a disk loading mechanism as a second mechanism. In a tape drive mechanism as another example of acoustic apparatus, the drive power transmission of a tape drive motor is selectively switched between pair of tape take-up reels.
In the above drive power switching systems, various attempts have been made for reliably rotating the driven gear together with the rocking member according to the direction of rotation of the main drive gear. For example, the driven gear is given a light rocking load with a spring or the like to give the rocking member a rocking force with the rotation load of the driven gear. As another example, the main drive gear is provided with a member providing slip friction, and the rocking member is given a rocking power with the rotational power of the member. As a further example, when the driven gear starts rocking together with the rocking member, the driven gear is caused to be in mesh with a stationary gear secured to a base plate.
Japanese Patent Laid-Open Publication No. 2000-298903 discloses a disc player provided with this type of drive power switching system.
Journal of Technical Disclosure published by Japan Institute of Invention and Innovation (JIII) No. 91-7600 discloses a rotation transmission switching system, in which according to the direction of rotation of a drive gear a transfer gear revolves about the drive gear to selectively switch the rotation route from the drive gear to a pair of driven gears.
With the prior art drive power switching system, for obtaining reliable rotation of the driven gear together with the rocking member, either an exclusive member for giving the driven gears or main drive gear rotational load is provided, or a stationary gear meshing with the driven gears is provided on a base plate. Therefore, the drive power switching system is complicated in construction, and also an undesired extra light rocking load is added to the drive power transfer route. Also, after the driven gears have been perfectly separated from the first gear, it is further revolved before it is brought into mesh with the second gear. Therefore, the drive power switching requires a certain interval of time.
The invention has an object of providing a drive power switching system for an acoustic apparatus, which can be simplified in construction and permits immediate drive power switching.